The Bendix hose coupling head, commonly known as a gladhand, used to connect the air brake lines between a tractor and a trailer. The HC-1 is typically not color-coded, allowing it to be used for either service or emergency air lines. The HC-2 has a unique design feature to prevent accidental cross-connection, ensuring that the emergency line cannot be hooked to the service line. The coupling design meets or exceeds SAE J318 requirements for air brake gladhands.